In the field of door locks or locking devices for doors, it is deemed necessary to provide such locks or devices that prevent unauthorized entry. The ordinary lock set generally includes a knob on either side of the door along with a tumbler and bolt mechanism associated with a latch plate and means for locking the tumbler from the inside of the door.
Additionally, secondary means in the form of night locks or latches are used as a deterrant to illegal entry, however the typical chain-connected device is only as strong as the screws that hold the chain support or anchor to the door trim. Another form of night latch includes a bolt carried in a retainer and slidable in a channel or slot therein and engageable with a catch or aperture in a member attached to the door jamb, or more commonly, to the door frame trim board.
Further, in view of the increased number of burglaries, the use of dead bolts has become quite common to provide extra protection. A typical dead bolt may include a tumbler operated by a key on the outside of the door and a turn knob on the inside to cause the bolt to move into and out of an opening in the door jamb.
Representative documentation in the field of door locks and like securing devices includes U.S. Pat. No. 827,624, issued to G. H. Foster on July 31, 1906, which discloses a door securer of generally flat sheet steel wherein one member is anchored in the door frame and includes a rivet or bolt slidable in a slot of an arm member clamped or snapped around the shank of the door knob.
U.S. Pat. No. 1,239,802, issued to R. A. Macbeth on Sept. 11, 1917, discloses a metal plate with lugs or ears at its opposite ends, one end having a lug with an aperture to accommodate a coupling rod hooked at one end thereof around the shank of the door knob and the other end providing a fork to accommodate a wing nut threaded on the coupling rod.
U.S. Pat. No. 1,894,913, issued to L. M. Sadler on Jan. 17, 1933, discloses a sliding doorlatch having a U-shaped housing and a latch extending through the housing along with a square shaft slidably engaging the latch and rotatable in the housing.
U.S. Pat. No. 2,536,352, issued to N. W. Butcher on Jan. 2, 1951, discloses a staple extension for padlocks having a metal rod for extending through a pair of securing loops and including a loop at one end of the rod for accommodating the padlock.
U.S. Pat. No. 3,633,955, issued to G. D. Read on Jan. 11, 1972, discloses a swinging door lock construction having a single L-shaped lock frame with an edge part forming a strike plate and extending along and secured to the door jamb. A bolt opening is formed through the juncture between the edge and side parts and slidably receives a sheet-like bolt.
U.S. Pat. No. Re 28,893, reissued to A. D. Adkison on July 6, 1976 (Reissue of U.S. Pat. No. 3,731,965, issued May 8, 1973), discloses a planar member between the door frame and the door with a tab disposed at a right angle to the member and adapted to be received in a notch. A pair of slots in the member present seats for receiving a keeper pin adjacent the door to present a dead bolt lock.
And, U.S. Pat. No. 4,004,833, issued to H. L. Hull on Jan. 25, 1977, discloses a door lock device comprising a lock bolt received upon the shaft of the door knob and extending into an aperture in a retaining plate attached to the door jamb.